net/nfc/llcp/commands.c

   1 /*
   2  * Copyright (C) 2011  Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the
  16  * Free Software Foundation, Inc.,
  17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
  21
  22 #include <linux/init.h>
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/nfc.h>
  26
  27 #include <net/nfc/nfc.h>
  28
  29 #include "../nfc.h"
  30 #include "llcp.h"
  31
  32 static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
  33         0,
  34         1, /* VERSION */
  35         2, /* MIUX */
  36         2, /* WKS */
  37         1, /* LTO */
  38         1, /* RW */
  39         0, /* SN */
  40         1, /* OPT */
  41         0, /* SDREQ */
  42         2, /* SDRES */
  43
  44 };
  45
  46 static u8 llcp_tlv8(u8 *tlv, u8 type)
  47 {
  48         if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
  49                 return 0;
  50
  51         return tlv[2];
  52 }
  53
  54 static u16 llcp_tlv16(u8 *tlv, u8 type)
  55 {
  56         if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
  57                 return 0;
  58
  59         return be16_to_cpu(*((__be16 *)(tlv + 2)));
  60 }
  61
  62
  63 static u8 llcp_tlv_version(u8 *tlv)
  64 {
  65         return llcp_tlv8(tlv, LLCP_TLV_VERSION);
  66 }
  67
  68 static u16 llcp_tlv_miux(u8 *tlv)
  69 {
  70         return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
  71 }
  72
  73 static u16 llcp_tlv_wks(u8 *tlv)
  74 {
  75         return llcp_tlv16(tlv, LLCP_TLV_WKS);
  76 }
  77
  78 static u16 llcp_tlv_lto(u8 *tlv)
  79 {
  80         return llcp_tlv8(tlv, LLCP_TLV_LTO);
  81 }
  82
  83 static u8 llcp_tlv_opt(u8 *tlv)
  84 {
  85         return llcp_tlv8(tlv, LLCP_TLV_OPT);
  86 }
  87
  88 static u8 llcp_tlv_rw(u8 *tlv)
  89 {
  90         return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
  91 }
  92
  93 u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
  94 {
  95         u8 *tlv, length;
  96
  97         pr_debug("type %d\n", type);
  98
  99         if (type >= LLCP_TLV_MAX)
 100                 return NULL;
 101
 102         length = llcp_tlv_length[type];
 103         if (length == 0 && value_length == 0)
 104                 return NULL;
 105         else if (length == 0)
 106                 length = value_length;
 107
 108         *tlv_length = 2 + length;
 109         tlv = kzalloc(2 + length, GFP_KERNEL);
 110         if (tlv == NULL)
 111                 return tlv;
 112
 113         tlv[0] = type;
 114         tlv[1] = length;
 115         memcpy(tlv + 2, value, length);
 116
 117         return tlv;
 118 }
 119
 120 int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
 121                           u8 *tlv_array, u16 tlv_array_len)
 122 {
 123         u8 *tlv = tlv_array, type, length, offset = 0;
 124
 125         pr_debug("TLV array length %d\n", tlv_array_len);
 126
 127         if (local == NULL)
 128                 return -ENODEV;
 129
 130         while (offset < tlv_array_len) {
 131                 type = tlv[0];
 132                 length = tlv[1];
 133
 134                 pr_debug("type 0x%x length %d\n", type, length);
 135
 136                 switch (type) {
 137                 case LLCP_TLV_VERSION:
 138                         local->remote_version = llcp_tlv_version(tlv);
 139                         break;
 140                 case LLCP_TLV_MIUX:
 141                         local->remote_miu = llcp_tlv_miux(tlv) + 128;
 142                         break;
 143                 case LLCP_TLV_WKS:
 144                         local->remote_wks = llcp_tlv_wks(tlv);
 145                         break;
 146                 case LLCP_TLV_LTO:
 147                         local->remote_lto = llcp_tlv_lto(tlv) * 10;
 148                         break;
 149                 case LLCP_TLV_OPT:
 150                         local->remote_opt = llcp_tlv_opt(tlv);
 151                         break;
 152                 default:
 153                         pr_err("Invalid gt tlv value 0x%x\n", type);
 154                         break;
 155                 }
 156
 157                 offset += length + 2;
 158                 tlv += length + 2;
 159         }
 160
 161         pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
 162                  local->remote_version, local->remote_miu,
 163                  local->remote_lto, local->remote_opt,
 164                  local->remote_wks);
 165
 166         return 0;
 167 }
 168
 169 int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
 170                                   u8 *tlv_array, u16 tlv_array_len)
 171 {
 172         u8 *tlv = tlv_array, type, length, offset = 0;
 173
 174         pr_debug("TLV array length %d\n", tlv_array_len);
 175
 176         if (sock == NULL)
 177                 return -ENOTCONN;
 178
 179         while (offset < tlv_array_len) {
 180                 type = tlv[0];
 181                 length = tlv[1];
 182
 183                 pr_debug("type 0x%x length %d\n", type, length);
 184
 185                 switch (type) {
 186                 case LLCP_TLV_MIUX:
 187                         sock->miu = llcp_tlv_miux(tlv) + 128;
 188                         break;
 189                 case LLCP_TLV_RW:
 190                         sock->rw = llcp_tlv_rw(tlv);
 191                         break;
 192                 case LLCP_TLV_SN:
 193                         break;
 194                 default:
 195                         pr_err("Invalid gt tlv value 0x%x\n", type);
 196                         break;
 197                 }
 198
 199                 offset += length + 2;
 200                 tlv += length + 2;
 201         }
 202
 203         pr_debug("sock %p rw %d miu %d\n", sock, sock->rw, sock->miu);
 204
 205         return 0;
 206 }
 207
 208 static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
 209                                        u8 dsap, u8 ssap, u8 ptype)
 210 {
 211         u8 header[2];
 212
 213         pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
 214
 215         header[0] = (u8)((dsap << 2) | (ptype >> 2));
 216         header[1] = (u8)((ptype << 6) | ssap);
 217
 218         pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
 219
 220         memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE);
 221
 222         return pdu;
 223 }
 224
 225 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
 226                                     u8 tlv_length)
 227 {
 228         /* XXX Add an skb length check */
 229
 230         if (tlv == NULL)
 231                 return NULL;
 232
 233         memcpy(skb_put(pdu, tlv_length), tlv, tlv_length);
 234
 235         return pdu;
 236 }
 237
 238 static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
 239                                          u8 cmd, u16 size)
 240 {
 241         struct sk_buff *skb;
 242         int err;
 243
 244         if (sock->ssap == 0)
 245                 return NULL;
 246
 247         skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
 248                                  size + LLCP_HEADER_SIZE, &err);
 249         if (skb == NULL) {
 250                 pr_err("Could not allocate PDU\n");
 251                 return NULL;
 252         }
 253
 254         skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
 255
 256         return skb;
 257 }
 258
 259 int nfc_llcp_disconnect(struct nfc_llcp_sock *sock)
 260 {
 261         struct sk_buff *skb;
 262         struct nfc_dev *dev;
 263         struct nfc_llcp_local *local;
 264
 265         pr_debug("Sending DISC\n");
 266
 267         local = sock->local;
 268         if (local == NULL)
 269                 return -ENODEV;
 270
 271         dev = sock->dev;
 272         if (dev == NULL)
 273                 return -ENODEV;
 274
 275         skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
 276         if (skb == NULL)
 277                 return -ENOMEM;
 278
 279         skb_queue_tail(&local->tx_queue, skb);
 280
 281         return 0;
 282 }
 283
 284 int nfc_llcp_send_symm(struct nfc_dev *dev)
 285 {
 286         struct sk_buff *skb;
 287         struct nfc_llcp_local *local;
 288         u16 size = 0;
 289
 290         pr_debug("Sending SYMM\n");
 291
 292         local = nfc_llcp_find_local(dev);
 293         if (local == NULL)
 294                 return -ENODEV;
 295
 296         size += LLCP_HEADER_SIZE;
 297         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 298
 299         skb = alloc_skb(size, GFP_KERNEL);
 300         if (skb == NULL)
 301                 return -ENOMEM;
 302
 303         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 304
 305         skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
 306
 307         __net_timestamp(skb);
 308
 309         nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_TX);
 310
 311         return nfc_data_exchange(dev, local->target_idx, skb,
 312                                  nfc_llcp_recv, local);
 313 }
 314
 315 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
 316 {
 317         struct nfc_llcp_local *local;
 318         struct sk_buff *skb;
 319         u8 *service_name_tlv = NULL, service_name_tlv_length;
 320         u8 *miux_tlv = NULL, miux_tlv_length;
 321         u8 *rw_tlv = NULL, rw_tlv_length;
 322         int err;
 323         u16 size = 0;
 324
 325         pr_debug("Sending CONNECT\n");
 326
 327         local = sock->local;
 328         if (local == NULL)
 329                 return -ENODEV;
 330
 331         if (sock->service_name != NULL) {
 332                 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
 333                                                       sock->service_name,
 334                                                       sock->service_name_len,
 335                                                       &service_name_tlv_length);
 336                 size += service_name_tlv_length;
 337         }
 338
 339         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
 340                                       &miux_tlv_length);
 341         size += miux_tlv_length;
 342
 343         rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &local->rw, 0, &rw_tlv_length);
 344         size += rw_tlv_length;
 345
 346         pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
 347
 348         skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
 349         if (skb == NULL) {
 350                 err = -ENOMEM;
 351                 goto error_tlv;
 352         }
 353
 354         if (service_name_tlv != NULL)
 355                 skb = llcp_add_tlv(skb, service_name_tlv,
 356                                    service_name_tlv_length);
 357
 358         skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
 359         skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 360
 361         skb_queue_tail(&local->tx_queue, skb);
 362
 363         return 0;
 364
 365 error_tlv:
 366         pr_err("error %d\n", err);
 367
 368         kfree(service_name_tlv);
 369         kfree(miux_tlv);
 370         kfree(rw_tlv);
 371
 372         return err;
 373 }
 374
 375 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
 376 {
 377         struct nfc_llcp_local *local;
 378         struct sk_buff *skb;
 379         u8 *miux_tlv = NULL, miux_tlv_length;
 380         u8 *rw_tlv = NULL, rw_tlv_length;
 381         int err;
 382         u16 size = 0;
 383
 384         pr_debug("Sending CC\n");
 385
 386         local = sock->local;
 387         if (local == NULL)
 388                 return -ENODEV;
 389
 390         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
 391                                       &miux_tlv_length);
 392         size += miux_tlv_length;
 393
 394         rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &local->rw, 0, &rw_tlv_length);
 395         size += rw_tlv_length;
 396
 397         skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
 398         if (skb == NULL) {
 399                 err = -ENOMEM;
 400                 goto error_tlv;
 401         }
 402
 403         skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
 404         skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 405
 406         skb_queue_tail(&local->tx_queue, skb);
 407
 408         return 0;
 409
 410 error_tlv:
 411         pr_err("error %d\n", err);
 412
 413         kfree(miux_tlv);
 414         kfree(rw_tlv);
 415
 416         return err;
 417 }
 418
 419 int nfc_llcp_send_snl(struct nfc_llcp_local *local, u8 tid, u8 sap)
 420 {
 421         struct sk_buff *skb;
 422         struct nfc_dev *dev;
 423         u8 *sdres_tlv = NULL, sdres_tlv_length, sdres[2];
 424         u16 size = 0;
 425
 426         pr_debug("Sending SNL tid 0x%x sap 0x%x\n", tid, sap);
 427
 428         if (local == NULL)
 429                 return -ENODEV;
 430
 431         dev = local->dev;
 432         if (dev == NULL)
 433                 return -ENODEV;
 434
 435         sdres[0] = tid;
 436         sdres[1] = sap;
 437         sdres_tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, sdres, 0,
 438                                        &sdres_tlv_length);
 439         if (sdres_tlv == NULL)
 440                 return -ENOMEM;
 441
 442         size += LLCP_HEADER_SIZE;
 443         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 444         size += sdres_tlv_length;
 445
 446         skb = alloc_skb(size, GFP_KERNEL);
 447         if (skb == NULL) {
 448                 kfree(sdres_tlv);
 449                 return -ENOMEM;
 450         }
 451
 452         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 453
 454         skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
 455
 456         memcpy(skb_put(skb, sdres_tlv_length), sdres_tlv, sdres_tlv_length);
 457
 458         skb_queue_tail(&local->tx_queue, skb);
 459
 460         kfree(sdres_tlv);
 461
 462         return 0;
 463 }
 464
 465 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
 466 {
 467         struct sk_buff *skb;
 468         struct nfc_dev *dev;
 469         u16 size = 1; /* Reason code */
 470
 471         pr_debug("Sending DM reason 0x%x\n", reason);
 472
 473         if (local == NULL)
 474                 return -ENODEV;
 475
 476         dev = local->dev;
 477         if (dev == NULL)
 478                 return -ENODEV;
 479
 480         size += LLCP_HEADER_SIZE;
 481         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 482
 483         skb = alloc_skb(size, GFP_KERNEL);
 484         if (skb == NULL)
 485                 return -ENOMEM;
 486
 487         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 488
 489         skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
 490
 491         memcpy(skb_put(skb, 1), &reason, 1);
 492
 493         skb_queue_head(&local->tx_queue, skb);
 494
 495         return 0;
 496 }
 497
 498 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
 499 {
 500         struct sk_buff *skb;
 501         struct nfc_llcp_local *local;
 502
 503         pr_debug("Send DISC\n");
 504
 505         local = sock->local;
 506         if (local == NULL)
 507                 return -ENODEV;
 508
 509         skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
 510         if (skb == NULL)
 511                 return -ENOMEM;
 512
 513         skb_queue_head(&local->tx_queue, skb);
 514
 515         return 0;
 516 }
 517
 518 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
 519                           struct msghdr *msg, size_t len)
 520 {
 521         struct sk_buff *pdu;
 522         struct sock *sk = &sock->sk;
 523         struct nfc_llcp_local *local;
 524         size_t frag_len = 0, remaining_len;
 525         u8 *msg_data, *msg_ptr;
 526
 527         pr_debug("Send I frame len %zd\n", len);
 528
 529         local = sock->local;
 530         if (local == NULL)
 531                 return -ENODEV;
 532
 533         /* Remote is ready but has not acknowledged our frames */
 534         if((sock->remote_ready &&
 535             skb_queue_len(&sock->tx_pending_queue) >= sock->rw &&
 536             skb_queue_len(&sock->tx_queue) >= 2 * sock->rw)) {
 537                 pr_err("Pending queue is full %d frames\n",
 538                        skb_queue_len(&sock->tx_pending_queue));
 539                 return -ENOBUFS;
 540         }
 541
 542         /* Remote is not ready and we've been queueing enough frames */
 543         if ((!sock->remote_ready &&
 544              skb_queue_len(&sock->tx_queue) >= 2 * sock->rw)) {
 545                 pr_err("Tx queue is full %d frames\n",
 546                        skb_queue_len(&sock->tx_queue));
 547                 return -ENOBUFS;
 548         }
 549
 550         msg_data = kzalloc(len, GFP_KERNEL);
 551         if (msg_data == NULL)
 552                 return -ENOMEM;
 553
 554         if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) {
 555                 kfree(msg_data);
 556                 return -EFAULT;
 557         }
 558
 559         remaining_len = len;
 560         msg_ptr = msg_data;
 561
 562         while (remaining_len > 0) {
 563
 564                 frag_len = min_t(size_t, sock->miu, remaining_len);
 565
 566                 pr_debug("Fragment %zd bytes remaining %zd",
 567                          frag_len, remaining_len);
 568
 569                 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
 570                                         frag_len + LLCP_SEQUENCE_SIZE);
 571                 if (pdu == NULL)
 572                         return -ENOMEM;
 573
 574                 skb_put(pdu, LLCP_SEQUENCE_SIZE);
 575
 576                 memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
 577
 578                 skb_queue_tail(&sock->tx_queue, pdu);
 579
 580                 lock_sock(sk);
 581
 582                 nfc_llcp_queue_i_frames(sock);
 583
 584                 release_sock(sk);
 585
 586                 remaining_len -= frag_len;
 587                 msg_ptr += frag_len;
 588         }
 589
 590         kfree(msg_data);
 591
 592         return len;
 593 }
 594
 595 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
 596                            struct msghdr *msg, size_t len)
 597 {
 598         struct sk_buff *pdu;
 599         struct nfc_llcp_local *local;
 600         size_t frag_len = 0, remaining_len;
 601         u8 *msg_ptr, *msg_data;
 602         int err;
 603
 604         pr_debug("Send UI frame len %zd\n", len);
 605
 606         local = sock->local;
 607         if (local == NULL)
 608                 return -ENODEV;
 609
 610         msg_data = kzalloc(len, GFP_KERNEL);
 611         if (msg_data == NULL)
 612                 return -ENOMEM;
 613
 614         if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) {
 615                 kfree(msg_data);
 616                 return -EFAULT;
 617         }
 618
 619         remaining_len = len;
 620         msg_ptr = msg_data;
 621
 622         while (remaining_len > 0) {
 623
 624                 frag_len = min_t(size_t, sock->miu, remaining_len);
 625
 626                 pr_debug("Fragment %zd bytes remaining %zd",
 627                          frag_len, remaining_len);
 628
 629                 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
 630                                          frag_len + LLCP_HEADER_SIZE, &err);
 631                 if (pdu == NULL) {
 632                         pr_err("Could not allocate PDU\n");
 633                         continue;
 634                 }
 635
 636                 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
 637
 638                 memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
 639
 640                 /* No need to check for the peer RW for UI frames */
 641                 skb_queue_tail(&local->tx_queue, pdu);
 642
 643                 remaining_len -= frag_len;
 644                 msg_ptr += frag_len;
 645         }
 646
 647         kfree(msg_data);
 648
 649         return len;
 650 }
 651
 652 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
 653 {
 654         struct sk_buff *skb;
 655         struct nfc_llcp_local *local;
 656
 657         pr_debug("Send rr nr %d\n", sock->recv_n);
 658
 659         local = sock->local;
 660         if (local == NULL)
 661                 return -ENODEV;
 662
 663         skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
 664         if (skb == NULL)
 665                 return -ENOMEM;
 666
 667         skb_put(skb, LLCP_SEQUENCE_SIZE);
 668
 669         skb->data[2] = sock->recv_n;
 670
 671         skb_queue_head(&local->tx_queue, skb);
 672
 673         return 0;
 674 }